<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>学习js</title>
		
		<style type="text/css">
			*{margin: 0;padding: 0;}
			.study_part{width:1000px; margin: 20px auto;padding: 20px; background: #EEEEEE;}
		</style>
	
        <script>
        function myFunction()
        {
        document.getElementById("demo").innerHTML="My First JavaScript Function";
        }
        </script>
    </head>
    
    <body>
        
        
        <div class="study_part">
        	<p id="demo">A Paragraph</p>
            <button type="button" onclick="myFunction()">Try it</button>
        </div>

        
        
        
        
        
        
        
        
        
        
        
        
        
        
        
    </body>
</html>
